Reuters) - Venezuelan President Nicolas Maduro offered asylum to former U.S. intelligence contractor Edward Snowden on Friday in defiance of Washington, which is demanding his arrest for divulging details of secret U.S. spy programs.

"In the name of America's dignity ... I have decided to offer humanitarian asylum to Edward Snowden," Maduro told a military parade marking Venezuela's independence day.

"He is a young man who has told the truth, in the spirit of rebellion, about the United States spying on the whole world."

The 30-year-old former National Security Agency contractor is believed to be holed up in the transit area of Moscow's Sheremetyevo international airport.

Russian officials have kept Snowden at arm's length since he landed from Hong Kong on June 23, saying the transit area where passengers stay between flights is neutral territory and he will be on Russian soil only if he goes through passport control.

It was not immediately clear how Snowden would react to Maduro's offer, nor reach Venezuela if he accepted.

There are no direct commercial flights between Moscow and Caracas, and the usual route involves changing planes in Havana. It is not clear if the Cuban authorities would let him transit.

Given the dramatic grounding in Vienna of the Bolivian president's plane this week over suspicions that Snowden was onboard, using European airspace could prove problematic.

One alternative flight plan would involve an aircraft taking off from Moscow, refueling in Vladivostok, and then continuing east over the Pacific to South America.

Russia has shown signs of growing impatience over Snowden's stay in Moscow. Its deputy foreign minister said on Thursday that Snowden had not sought asylum in that country and needed to choose a place to go.

Moscow has made clear that the longer he stays, the greater the risk of the diplomatic standoff over his fate causing lasting damage to relations with Washington.

The White House declined to comment on Maduro's offer.

Raising the possibility of at least one other option, Nicaragua said it had received an asylum request from Snowden and could agree to it "if circumstances permit".